I have two VN installed on my Windows 8.1 x64:
Hana to Otome ni Shukufuku wo Royal Bouquet
Mahou Shoujo no Taisetsu na Koto,
but to no avail. Everytime i open the *.exe, it's only appeared for a split second before disappeared again. Funny enough, when i trying to play it on Windows 8.1 x86...